Thiazolesulfenamides



2,7 6 6,237 THIAZOLESULFENAMIDES John J. DAmico, Charleston,

santo Chemical Company, tion of Delaware No Drawing. ApplicationSeptember 17, 1953, Serial No. 380,873

17 Claims. (Cl. 260-2471) W. Va., assignor to Mon- St. Louis, Mo., acorporawhere n is a whole number, where R and R are hydrogen orhydrocarbon radicals and where R is a primary nonaromatic amine residueor a heterocyclic secondary amine residue containing a hetero nitrogenatom attached to the sulfur atom, are a class of highly usefulcompounds.

The monothiazolyl compounds falling within the scope of this inventionare those of the aforedescribed formula wherein n is one. Typicalexamples of this group are those wherein R is a primary amine residue ofthe structure NA where A is methyl, ethyl, n-propyl, isopropyl, n-butyl,secbutyl, isobutyl, tert-butyl, n-amyl, isoamyl, sec-amyl, nhexyl,2-ethylhexyl, cyclohexyl, a-methylcyclohexyl, ozethylcyclohexyl,furfuryl, tetrahydrofurfuryl, benzyl, 8- phenethyl, Z-hydroxyethyl,3-hydroxy-n-propyl, hydroxytert-butyl, and the like. Of this group thethiazolesulfenamides wherein A is a branched chain alkyl radical,especially one having a tertiary carbon linked to the nitrogen, i. e.tert-butyl, are preferred.

A particularly valuable group of compounds within the new class ofthiazolesulfenamides are those in which R" is a heterocyclic secondaryamine residue such as morpholinyl, piperidyl, a-methyl piperidyl,-methyl piperidyl, and like heterocyclic secondary amine residues. Alsoincluded in this valuable group are the bis-thiazolyl sulfenamides ofpiperazine and the various alkyl substituted piperazines such as2,5-dimethyl-piperazine. The piperazine derivatives may be representedas follows:

Other bisthiazolyl sulfenamides falling within the scope of the presentinvention are those of the aforedescribed formula wherein n is two andwherein R" is In general it is preferred that R and R in the fore-States Patent 2,766,237 Patented Get. a, was

2 going formulae be short chain alkyl radicals such as methyl, ethyl,propyl, and butyl, but it is to be understood that higher alkyl radicalssuch as amyl, hexyl, octyl,

etc., as well as alicyclic radicals such as cyclohexyl, aral- EXAMPLE 14 methyl 2(4 morpholinylsulfenyl) 5 thiazolecarboxylic acid An aqueoussolution containing 43.8 grams (0.25 mole) of2-mercapto-4-methyl-5-thiazolecarboxylic acid (BeiL, 4th edition, vol.27, p. 339), grams of water, and 40.0 grams (0.25 mole) of a 25% aqueoussodium hydroxide solution was prepared in a one liter narrow beakerequipped with a mechanical mixer, dropping funnel, ice bath, andthermometer. To this solution at 15 C., 65.5 grams (0.75 mole) ofmorpholine was added at such a rate that the reaction did not exceed atemperature of 27 C. The mixture was cooled to 13 C. and 42 ml. of 25%sulfuric acid was added dropwise at 13-l5 C. in 20 minutes. To thismixture at 1320 C. there was added, drop by drop, with stirring over aperiod of 2 hours, ml. (15.0 g./ 100 ml.) of sodium hypochloritesolution. The excess sodium hypochlorite was destroyed by the additionof one gram of sodium sulfite. The reaction mixture was cooled to 10 C.,extracted with 500 ml. of ethyl ether, the ether extract washed withwater until the washings were neutral to litmus, dried over sodiumsulfate, and finally the ether removed in vacuo. The residue was a whitesolid, M. P. 56-57 C. Analysis gave 10.34% nitrogen and 24.75% sulfur ascompared to 10.76% nitrogen and 24.63% sulfur calculated forC9H12N2O3S2.

EXAMPLE 2 4 (5 -carbethoxy-4-methyl-2-th iazolylsulfenyl morpholine Anaqueous solution containing 24.4 grams (0.12 mole) iodide. After aboutone-tenth of the iodine solution had been added, the sulfenamide beganto separate in the form of white crystals. The product was filtered 01f,washed with water until free from alkali, and air dried at roomtemperature. The product, a white solid, M. P. 53-54 C., was obtained in66% yield.

The yield was somewhat better by the following procedure: 1

Heptane (1200 ml.) and 39 grams (0.0964 mole) of2,2'-dithio-bis-(5-carbethoxy-4-methyl thiazole) were charged in a twoliter, three-necked flask, equipped with a thermometer, condenser,mechanical stirrer, and a Glas- Col mantle. The mixture was heated to 50C. and 19.2 grams (0.22 mole) of morpholine was added to this solution.The reaction mixture was heated at 50 C. for one hour. After cooling to25 C., the morpholine salt of the mercaptothiazole was recovered byfiltration. The filtrate was extracted with 500 ml. of 2% aqueous sodiumhydroxide, then washed with water until the washings were neutral tolitmus, and the heptane was removedin vacuo at 35-40" C. The residue wascooled to 10 C., and the precipitate filtered otf, washed with water,and air dried at 25 C. The product, a white solid, M. P. 53-54 C., wasobtained in 76% yield. Analysis gave 9.70% nitrogen and 22.49% sulfur ascompared to 9.71% nitrogen and 22.23% sulfur calculated for CnHrsNzOaSz.

EXAMPLE 3 4-(5-carb0methoxy-4-melhyl-2-thiaz0lylsulfenyl morpholine Anaqueous solution containing 45.2 grams (0.24 mole) ofS-carbomethoxy-4-methyl-Z-thiazolethiol, 77 grams. of 25% aqueous sodiumhydroxide in 250 ml. of water and 209.5 grams (2.4 moles) of morpholinewas prepared in a two liter beaker equipped with a mechanical mixer,dropping funnel and thermometer. To this solution at 25 C. there wasadded, drop by drop, with stirring over a period of 75 minutes, 61.2grams of iodine dissolved in 800 ml. of water containing 80 grams ofpotassium iodide. After a small proportion of the iodine solution hadbeen added the sulfenarnide began to separate in the form of whitecrystals. The product was filtered ofi, washed with water until freefrom alkali and air dried at room temperature. A white solid, M. P.123-124 C., was obtained in 38% yield.

Oxidation with sodium hypochlorite as follows gave better results: Anaqueous slurry was prepared contain ing 50 grams (0.26 mole) of5-carbomethoxy-4-1nethyl- 2 -thiazolethiol, 150 grams of water, and 24.8grams (0.29 mole) of morpholine in a one liter narrow beaker equippedwith a thermometer, mechanical mixer, dropping funnel, and hot waterbath. To this mixture, at 5.052 C., there was added, drop by drop withstirring in 50 minutes, 160 ml. (14.6 g/l ml.) of sodium hypochlorite.After cooling to 10 C. the precipitate was filtered off, washed withwater until the washings were neutral to litmus, and air dried at roomtemperature. The product, a white solid, was obtained in 78.5% yield.After recrystallization from ethyl alcohol, it melted at 123l24 C.Analysis gave 10.00% nitrogen and 23.50% sulfur as compared to 10.21%nitrogen and 23.38% sulfur calculated for CroHmNaOsSz.

Employing the second procedure of Example 3 but replacing morpholinewith an equinolecular proportion of piperidine there is obtained-carbomethoxy-N-piperidyl- 4-methyl-2-thiazole sulfenamide.

Employing the second procedure ofExample 3 but replacing morpholine withan equimolecular proportion of piperazine there is obtained1,4-bis-(5-carbomethoxy-4- methyl-Z-thiazolylsulfenyl) piperazine.

EXAMPLE 4 4.-(S-carbobutoxy-4-methyl-2-thiazolylsulfenyl morpholine Anaqueous solution containing 1155 grams (0.5 mole) ofS-carbobutoxy-4-rnethyl-2-thiazolethiol, 160 grams of 25% aqueous sodiumhydroxide and 436 grams (5.0 moles) of morpholine in 2000 ml. of waterwas prepared and charged into a suitable reactor fitted with amechanical mixer, dropping funnel and thermometer. To thissolution at 25f C. there was gradually added with stirring 128 grains of iodine in1700 ml. of water con-. taining 138 grams of potassium iodide. Aboutfour hours was consumed in the addition of this solution and stirringwas. continued for another half hour and the reaction mixture cooled toC., the solids filtered oif and washed until the washings were neutralto litmus. The semi-solidproduet was dried at room temperature. Thyield. was 66 grams or 41.7% of theory.

4 EXAMPLE 5 5-carb0methoxy-N-cycl0hexyl-4-methyl-2 -th iazolesulfenamideAn aqueous solution containing 45.4 grams (0.24 mole) of5-carbomethoxy-4-rnethyl-2-thiazolethiol, 77 grams of 25% aqueous sodiumhydroxide in 200 ml. of water, and 237.6 grams (2.4 moles) ofcyclohexylamine was prepared in a two liter beaker equipped with a;mechanical mixer, dropping funnel, and a thermometer. To this solutionat 25 C., there was added, drop bydrop, with stirring over a period oftwo hours, 91.7 grams of iodine dissolved in 1200 ml. of watercontaininggrams of potassium iodide. After about one-tenth of the iodine solutionhad been added, the sulfenarnide began to separate in the form of whitecrystals. The reaction mixture was extracted with 70 ml. of ethyl ether,the ether solution washed with water until free from, alkali and theether removed in vacuo. luted with water and the solid removed byfiltration and dried at room temperature. 45 grams representing a yieldof 65.5% of theoretical was obtained as a cream solid, M. P. 55-57 C.Analysis gave 9.89% nitrogen and 22.62% sulfur as compared to 9.78nitrogen and 22.39% sulfur calculated for C12H1BN2O2S2.

EXAMPLE 6 5 -carb0but0xy-N cycloh' exyl-4-methyl-2 -thiazolesul fenamideEXAMPLE 7 5 -carbeth0xy-N -isopropyl-4-methyl-2-th iazolesul fem amideAn aqueous solution. containing 45.4 grams (0.24

mole) of S-carbomethoxy-4-methyl-2-thiazolethiol, 77 grams of*25'%aqueous sodium hydroxide in 200 ml. of

water, and 141.8 grams (2.4 moles) of monoisopropylamine was prepared-ina two liter beaker equipped with a mechanical mixer, dropping funnel,and a thermometer. To this solution at 25 0;, there was added, drop bydrop, with stirring over a period of two hours, 51.7 grams of iodinedissolved in 1200 ml. of water containing 120 grams of'potassium iodide.After about one-tenth of the iodine solution had been added, thesulfenamide, began to separate in the form of crystals. The reactionmixture was cooled to10 C. and the solid then removed by filtration,washed with water until free from alkali and air dried at roomtemperature. 29 grams representing a yield of 49.1% of a yellow, solid,M. P. 57'-58 C., was. obtained. Analysis gave 11.50% nitrogen and 25.78%sulfur as compared to 11.3% nitrogen and 26.03 sulfur calculated forCsHmNzOzSz.

Employing. the procedure of Example 7*but-replacing monoisopropllamiuewith an, equimolecular proportion.

of n-propylamine 5-carbomethoxyrN-n-propyllanethyl-2-thiazole-sulfenamide is obtained.

EXAMPLE 8 mole) of 5-carboethoxy-4-methyl-2-thiazolethiol, 77 of; 25%aqueoussodiurnmydroxide in 200;ml..of

The residue was (1i,

Water and 141.8 grams (2.4-moles) of-monoisopropyl-- amine was preparedina two liter-beaker equipped with a mechanical mixer, dropping funneland a thermometer. To this solution at 25 C. there was added, drop bydrop, with stirring over a period of two hours, 91.7 grams of iodine in1200 ml. of water containing 120 grams of potasium iodide. Thereaction-mixture was extracted with 700 ml. of ether and the ethersolution washed with water until free from alkali and the ether removedin vacuo. The residue was a dark amber oil obtained in a yield of 48%theoretical. Analysis gave 24.10% sulfur as compared to 24.63% sulfurcalculated for C1oH1sN2O2S2.

EXAMPLE 9 -carbomethoxy-N tert-butyl-4-methyl-Z-thiazolesulfenamide Anaqueous solution containing 48.3 grams (0.25 mole) of5-carbomethoxy-4-methyl-Z-thiazolethiol, 80 grams (0.5 mole) of 25%aqueous sodium hydroxide in 1000 ml. of water, and 182 grams (2.5 moles)of tert-butylamine was prepared in a suitable reaction vessel equippedwith a mechanical mixer, dropping funnel, and a thermometer. To thissolution was added drop by drop with agitation over a period of abouttwo hours 64 grams of iodine dissolved in 850 ml. of water containing 69grams of potassium iodide. The reaction mix was then stirred for anadditional 30 minutes and then cooled to about C. The reaction mix wasthen filtered and the filter cake washed with water until free fromalkali, and then dried at room temperature. 16 grams of the product wasobtained as a cream colored solid melting at 144 C. Analysis gave 10.46%nitrogen as compared to 10.75% nitrogen calculated for C10H16N202S2.

Employing the procedure of Example 9 but replacing tert-butylamine withan equimolecular proportion of isobutylamine 5- carbomethoxy Nisobutyl-4-methyl-2 thiazolesulfenamide is obtained.

EXAMPLE 10 a 5 carbethoxy-N-tert-butyl-4-methyI-Z-thiamlesulfenamide Anaqueous solution containing 48.8 grams (0.24 mole) of5-carbethoxy-4-methyl-Z-thiazolethiol, 77 grams (0.48 mole) of 25aqueous sodium hydroxide in 200 ml. of water, and 175.2 grams (2.4moles) of tert-butylamine was prepared in a suitable reaction vesselequipped with a mechanical mixer, dropping funnel, and a thermometer. Tothis solution was added drop by drop with agitation over a period ofabout onehour 91.7 grams. of iodine potassium iodide. The reaction mixwas then filtered and dissolved in 1200 ml. of water containing 120grams of 6 ether was removed in vacuo. solid, melting at 45-47 C., wasobtained in 70.1% yield. Analysis gave 21.34% sulfur as compared to21.20% sulfur calculated for C13H22N2O2S2.

EXAMPLE 12 S-cafbomethoxy-N- (hydroxy-terr-butyl) -4-methyl-2-thiazolesulfenamide To an agitated solution containing 47.3 grams (0.25mole) of 5-carbomethoxy-4-methy1-2-thiazolethiol 200 ml. of water, 80grams (0.25 mole) of 25 aqueous so-" dium hydroxide and 222.9 grams (2.5moles) 'of Z-amino- Z-methyl-l-propanol was added drop by drop over aperiod of one hour 91.7 grams of iodine dissolved in 1200 ml. of watercontaining 120 grams of potassium iodide. The mix was stirred for anadditional 30 minutes, cooled to 10 C. and extracted with 500 m1. ofdiethyl ether. The ether extract was washed with water to remove thealkali, dried, and then the ether was removed in vacuo. The productmelting at 108-110 C. was obtained in a 29% yield. Upon recrystallizingfrom heptane, it melted at 116118 C. Analysis gave 9.72% nitrogen and23.00% sulfur as compared to 10.13% nitrogen and 23.70% sulfurcalculated for C1oH1s-N2OsSz.

EXAMPLE 13 5 -carbeth0xy-N-(hydroxy-tert-butyl -4-methyl-2-thiazolesulfenamide To an agitated solution containing 50.9 grams (0.25mole) of 5-carbethoXy-4-methyl-2-thiazolethiol, 200 ml. of water, 80grams (0.25 mole) of 25% aqueous sodium hydroxide and 222.9 grams (2.5moles) of 2-amino-2- methyl-l-propanol was added drop by drop over aperiod The product, a'tan colored of one and one-half hours 91.7 gramsof iodine dissolved in 1200 ml. of water containing 120 grams ofpotassium iodide. The reaction mix was stirred for an additional twohours and then filtered. The filter cake was then washed free of alkaliand dried at room temperature. The product melting at 97-98 34.4% yield.Analysis gave 9.41% nitrogen and 22.10% sulfur as compared to 9.64%nitrogen and 22.08% sulfur calculated for C11H1sN2O3Sz.

EXAMPLE l4 mole) of 5-carbobutoxy-4-methyl-2-thiazolethiol, 200 ml.- ofwater, 66.5 grams of 25 aqueous sodium hydroxide and 185.6 grams (2.08moles) of Z-amino-Z-methyl-lthe filter cake washed with-water until freefrom alkali,

and then dried at room temperature. 37 grams of the product was obtainedas a cream colored solid melting at 9293 C. Analysis gave 10.33%nitrogen and" 23.43% sulfur as compared to 10.21% nitrogen and 23.39%sulfur calculated for CuHmNaOzSz.

EXAMPLE ll An aqueous solution containing 55.5 grams (0.24 mole) of5-carbobutoxy-4-methyl-2-thiazolethiol, 80 grams (0.5 mole) of 25%aqueous sodium hydroxide in 200 m1. of water, and 175.2 grams (0.24mole) of tert-butylamine was prepared in a suitable reaction vesselequipped with a mechanical mixer, dropping funnel, and a thermometer. Tothis solution was added drop by drop with agitation over a period ofabout one hour 91.7 grams of iodine dissolved in 1200 ml. of watercontaining 120 grams of potassium iodide. The reaction was cooled toabout 10 C. and then extracted with 500 ml. of diethyl ether. The ethersolution was then washed free of alkali with water and the so treatedsolution dried and then the iodide.

propanol was added drop by drop over a period of one and one-half hours76.5 grams'of iodine dissolved in 1000 ml. ofwater containing grams ofpotassium The reaction mix was stirred for an additional one and oneha'lf hours, cooled to 10 C. and filtered. The filter cake was thenwashed free of alkali and dried at room temperature. The product meltingat 68-70"v C. was obtained in a 56% yield. Analysis gave 20.36% sulfuras compared to 20.14% sulfur calculated for C13H22N203S2.

The new thiazolesulfenamides may be used as antiseptics, germicides,fungicides, etc. Many of the new thiazolesulfenamides are characterizedby strong catalytic activity for accelerating the vulcanization ofsulfur-vulcanizable rubbers both natural and synthetic. Many of the newthiazolesulfenamides provide a degree of process ing safety unattainablewith accelerator-s heretofore available. This is particularly true withrespect to the new thiazolesulfenamides wherein R" of the aforedescribedstructural formula is a 6-membered heterocyclic secondary amine residuecontaining not more than two hetero atoms, one of which being nitrogen,and at least four carbon atoms in the ring and consisting of carbon andhydrogen atoms in addition to the hetero atom (or atoms).

C. was obtained in a Stock A B Smoked sheets rubber parts by weight...100 100 Furnace carbon black -.d 50 50 Zinc odde do 5 Saturatedhydrocarb oft do 10 Stearic acid do 2 2 Condensation p of p-aminobiphenyl and acetone parts by weight 1. 5 1. 5 N-cyclohexyl2'benzothiazo1esulfenamide do 0. 8 r 4- (5-carbethoxy-4-niethyl-2-thiazo1ylsulfenyl)mor- 0 8 pholine parts by weighL.1

The stocks so compounded were cured in the usual manner by heating in apress for 30 minutes at 144 C. The physical properties of thevulcanizates illustrate the powerful accelerating action of thenewcompounds.

TABLE I Modulus of Elasticity Tensile at Ultimate Stock in lbs/in. Breakin V Elongaat Elongalbs/in." tion,

tion of Percent In addition the processing safety of. the vulcanizablecompositions was evaluated by means of a Mooney plas tometer at 121 C.The time to prevulcanize or scorch is taken as the time in minutes atwhichthe plasticity curve begins to rise continuously and sharply.

TABLE II Mooney Stock Search 111 mins.

at 121 C.

Several S-carbalkoxy N,N-dialkyl-Z-thiazolesulfenaabout one-half that ofthe commercial delayed action accelerator N cyclohexyl 2'benzothiazolesulfenamide.

Additionally S-carbomethoxy-N,N-didsopropy1-4-methy1-Z-thiazolesulfenamide, an amber oil (nitrogen 9.47% and sulfur- 22.84%its-compared to- 9.71% nitrogen and 22.23% sulfur calculated forCmHzoNzSzOzlwas prepared and evaluatedin a rubberformulation-andfound-"torexhibit less delayed 'action thanthat"employing-N-cyclohexyl-Z-benzothiazolesulfenamide as thevulcanizationaccelerator.

As 'anexampleofdelayed actionina gum stock, again 7 as compared to thesame--commercialdelayed action accelerator, rubber stocks werecompounded comprising Stock Smoked sheets rubber -parts by weight.

Zinc oxide do Stearic acid.

Sulfur N -cyclohexyl Z-benzothiazolesulfenamide; d

4Methyl-2(4-m0rpholinylsulfenylbS-thiazole lie acid .partslby weighL.

TABLE III Modulus oi Elasticity in lbs/111. at Elongation of 500%Tensile at Break .in lbsz/iu.

Ultimate Elongation, Percent Cure Time in Mins.

Stock,

CUTE. 1, 670 1, e05

In addition the processing safety'was evaluated using theMooneyplastometer inrthe manner described. The.

stock containing the. carboxyl substituted sulfenamide showed noevidenceof. scorch for the duration of the test.

T-AB LEIV Mooney Stockn Scorchin. mins. at

As still further examples of accelerating activity and processing safety1n the-presence of. furnace carbon black, rubber stocks were compounded.compnsing Stock E" F G H Pale crepe rubber..parts by weight" 100 100 100100 Furnace carbon black .do- 5t) 50 50 50 Zinc oxide .,do,. 5 5 5 5Saturated hydrocarbon softener parts by weight..- 3 3 3 3 Stearic acid6. 2 2. 2 2

fur-.. 2.5 2.5 2.5 2. 5 Coudensati. oduclr of p-amino,

bipbenyl andacetone.

parts by weight 1.5 1. 5 1. 5 l. 5 N-cyclohexyl2-benzothiazolesulfenamide parts by weight. 0. 8 4- (5-earbomethoxy-4-methyl-2-thiazolylsulfenybmorpholine.

parts by weight... I 8 4-(5carbethoxy-4-methyl-2-thia-"zolylsultenyDmorpholiue.

parts by weight 0.8 4-M e tb y l-2(4-rnorph01inylsulfenyl)51thiazolecarboxylie aeid,,

parts by weight 0. 8',

The stocks so compounded were cured in the usual manner by heating in apress for 30 minutes at 144 C. The accelerating activity was comparableto that of the commercial control in every case. The data are set forthbelow:

TABLE V Modulus of Elastic- Tensile at Ultimate Stock ity in Break inElongalbs/in. at lbs./iu. tion, per- Elongation cent Again the timerequired for prevulcanization was evaluated by the Mooney plastometer inthe manner abovedescribed. It will be noted that all of the acceleratorsare of the delayed action type.

TABLE VI Mooney Stock Scorch in mins. at 135 C.

E 5 F 5 G 6 H 5 Similar tests were carried out with formulationscomprising Stock I K L Pale crepe rubber parts by weight 100 Furnacecarbon black d 50 Zinc oxide 5 Stearic acid 2 Saturated hydrocarbonsoftener 3 Sulfur d 2. N-Cyciohexyl 2-benzothiazolesulfenamide parts byweight 0.8

5- Carbomethoxy-N- cycloliexy -4-methyl-2- thiaz0lesu1fenan1ide parts byweight 5- Carbomet TOXY- N-isopropyl- 4-metbyl- 2- thiazolesuilenamide.parts by weight The stocks so compounded were cured by heating in apress for 30 minutes at 144 C. Additionally the scorch time wasdetermined at 121 C. employing the Mooney plastometer as described.

TABLE VII Modulus of Elas- Tensile at Ult. Mooney Stock ticity in Breakin Elong., Scorch lbs./in. at lbs./in. percent in mins. Elongation at121 0.

Replacing the accelerator by5-carbomethoxy-N,N-diethyl-4-methyl-2-thiazolesulfenamide in theforegoing formulation resulted in a compound having inadequateprocessing safety.

As illustrative of the properties in a synthetic rubber stockcompositions were compounded comprising Stock Butadienc-styrenccopolymer (GR-S 100) parts by weight..

Furnace carbon black 0 Saturated hydrocarbon softener N -Oyc1ohexy1amide parts by weight 4 (fi-Carbcthoxy 4 methyl 2-thiazolylsulfeny1)morpho1ine.

parts by weight4-(5-Carbomethoxy-4-methyl-2-thiazolylsulfcnybmorpholine.

parts by weight" 5 Oarbomethoxy N isopropyl 4methyl-2-thiazolesnlfenamide.

parts by weight The stocks so compounded were cured by heating in apress at 144 C.

TABLE VIII Modulus of Cure Elasticity Tensile at Ultimate Stock Time inin lbs/in. Break in Elongation,

Mins. at Elongalbs/in. percent tion of 300 1W 60 1,660 3,196 543 N 60 1,745 3,235 500 O 60 1, 843 3, 270 535 P 60 2, 030 3, 370 470 M l, 780 3,350 530 N 90 l, 960 3, 365 520 O 90 1, 935 3, 325 490 P 90 2, 070 3, 445

The processing safety was evaluated at C. employing The Mooneyplastometer as described.

TABLE IX Mooney Stock Scorch in mins. at 135 C.

The new sulfenamides show marked acceleration in butyl rubber althoughthe order of activity is not necessarily the same as in natural rubber.The following compositions were cured by heating in a press fordifferent periods of time at 165.5 C. p-Quinone dioxime is a well-knownaccelerator and vulcanizing agent es It is of interest that replacementof 4-(5-carbomethoxy- 4-methyl-Z-thiazolysulfenyl)morpholine by the sameamount of 4-(5-earbethoxy-4-rnethyl-2-thiazolylsulfenyl)- morpholineresulted in weal; accelerating action, the modulus and tensile strengthof the vulcanizates being no more than half those shown above althoughthe compounds are comparable in other type polymers. The stockcontaining p-quinone dioxirne cured during the pro-heating period beforeany readings could be' re corded on the Mooney plastometer. Stock Rshowed no evidence of cure after 30 minutes at 135 C. and the scorchtime of Stock S was 8 minutes.

Further examples of the new sulienarnides were evaluated in naturalrubber compositions and were found to exhibit marked delayed action.However, at curing temperature they exhibited fast accelerating action,Compositions were compounded comprising Stock T U V Smoked sheets rubber100 100 100 Furnace carbon black 50 50 50 Zinc oxide 5 5 Stearie aciddo. 2 2 2 Saturated hydrocarbon softener do 3 3 3 Sulfur do 2. 5 2. 5 2.5 Reaction product of p-am ino biphenyl and acetone parts by weight" 1.5 1.5 l. 5 N cy c 1 oh e xyl 2-benzothiazolesulfenarnide parts byweight" 0. 8

sulfenyl) morpholine parts by weight O. 8 5 c a, rb 0 b u t oxy-N-eyclohexyli-m e t h y 1-2- thiazolesulfenamlde parts by weight" "i0. 8

The stocks so compounded were cured in the usual manner by heating in apress for different periods of time at i429 C. The physical propertiesexhibited by the 15 minute cures are reproduced below and indicate thatthe compounds are fast powerful accelerators at curing tem- In spite ofthe activity at curing temperature, the compositions were relativelyinactive at lower temperatures. Thus, the processing safety wasevaluated by means of the Mooney plastometer as described.

TABLE XII Mooney Scorch ln'Mins; Stock at 121 C.' at 135 C.

oqoooo Additionally as illustrative of'the propertiesbfthe newthiazolesulfenamides'ofthis invention rubber composi-- tions werecompounded: comprising Stock W X Smoked sheets rubber parts by weight.100 Furnace carbon black". do. 50 50 Zinc oxide do 5 5 Stearic acid do 22 Saturated hydrocarbon softener; do 3 3 Sulfur do 2. 5 2. 5N-cyclohexyl 2Fbenzothiazolesulfenamide do 0.8 N-tert-butyl-5-earbe thoxy-4-rnethyl-2-thl a z olesulfenamide parts by weight The stocks socompounded were cured in the usual manner by heating in a press for 15minutes at 142 C. The physical properties obtained are set forth below:

TABLE XIII Modulus of Elastic- Tensile at Ult. Mooney ity in Break inElong. Scorch lbs/in. at lbs/in. percent in mins. Stock Elongaat 121 C.

tion'of' 300% W 2, 900 4, 223 450 9 X s, 4,395 430 12 As still furtherillustrative of the properties of the thiazolesulfenamides of thisinvention synthetic rubber stocks were compounded comprising Stock AA BBCG DD Butadiene-styrene eopolymer (GR-S 0) parts by, weight" 100 100 100100 Furnace carbon black" do. 50' 50' 5D 50' Zinc oxide do 4. 4 4 4Saturated hydrocarbon softener 10 '10 l0 l0 Stearic acid d0- 2 2 2 2.Sul u r do 1.75 1.75 1. 75 l. 75 N- cy cl 0 h e xyl z benzothiazolesultenamide "parts by weight.-. 1; 2.N-tert-butyl-5-carb0methoxy-etmethyI-Z-thiazolesulfenamide parts byweight.- 1. 2-. N-tert-butyl-5-carb ethoxy-4 methyl-2-thiazolesulfenamide parts by weight" 1'. 2' N-hydroxy-tert-butyl)-5-carbet oxy-4-methyl-2-thiazolesulfenamide "partsby weight" 1. 2

The stocks so compounded were cured in the usual manner by heating in apress'for '90-rninutes at 144 C. The physical properties obtainedare-set forth below as well as the scorch times of the respective stocksas measured by the Mooney plastometer at"l 35 C.

TABLE XIV I Modulus otElastic- Mooney ity in Tensile ati Ultl' Scorch"Stock lbs/n1. Break in E1ong., inmins."

- atElonge lbs/in. percent at C.

tinn of 300% 1,820 3; 690 590" 28' 2,126 3,423- 466 es 2, 02a 3, 595500' 36 2, 030 3,460 460 36* Stck EE FF Smoked sheets rubber parts byweight. 100 100 Furnace carbon black d 50 50 Zinc oxide do 5 Stearicacid d0 2 2 Saturated hydroca on softener .do 3 3 Sulfur do 2. 5 2. 5N-cyclohexyl 2-benzothiazolesulfenamid .do Or 8fi-carbomethoxy-N-(hydroXy-tert-butyl) -4-m e th yl -2-thiazolesulfenamide parts by weight 0.8

The stocks so compounded were cured in the usual manner by heating in apress for 15 minutes at 142 C. The physical properties obtained are setforth below:

The scorch times of Stocks EE and FF as measured on the Mooneyplastometer at 121 C. were found to be the same, namely 16 minutes.

The new sulfenamides form reaction products with dimethylolurea whichare valuable accelerators for vulcanizing sulfur-vulcanizable rubbers.Similarly they form addition products with zinc chloride. The zincchloride adducts possess accelerating activity comparable to the parentmaterials. Zinc chloride adducts are formed by associating a solution ofzinc chloride with a solution of the sulfenamide. For example, admixinganhydrous ether solutions of4-(5-carbomethoxy-4-methyl-2-thiazolylsulfenyl)morpholine and zincchloride USP resulted in precipitation of the desired addition product.After standing 20 hours the solids were filtered off. The product meltedat 95-100" C. Analysis indicated that a mole to mole addition productformed. The sol-id product obtained in similar manner from zinc chlorideand 4-(5- carbethoxy-4-methyl-2-thiazolylsulfenyl) morpholine melted at7585 C. Again analysis indicated that a mole to mole addition productwas formed.

By the term sulfur-vulcanizable rubber as employed in the specificationis meant to include natural as well as synthetic rubbers which arecapable of vulcanization when heated with sulfur and is intended toinclude latices and reclaims thereof whether or not admixed withfillers, softeners, pigments, antioxidants, etc.

While this invention has been described with respect to certainembodiments it is not so limited and it is to be understood that variouschanges and modifications may be made without departing from the spiritor scope of this invention.

This case is a continuation-in-part of application Serial No. 294,929,filed June 21, 1952, now abandoned.

What is claimed is:

1. As new chemical compounds thiazolesulfenamides of the structuralformula where n is a whole number less than three equal to the number ofamino groups in R, where R and R are selected from the group consistingof hydrogen and hydrocarbon radicals containing less than 9 carbonatoms, and where R" is a radical containing less than nine car- 14 bonatoms having nitrogen attached to the sulfur selected from the groupconsisting of morpholinyl, piperidyl, piperazyl and lower alkylsubstituted derivatives thereof, an

where R and R are lower alkyl radicals.

3. As new chemical compounds thiazolesulfenamides of the structuralformula where R, R and A are lower alkyl radicals.

4. As new chemical compounds thiazolesulfenamides of the structuralformula where A is a lower alkyl radical.

5. 4 (5 carbomethoxy 4 methyl 2 thiazolesulfenyl)-morpholine.

6. 4 (5 carbethoxy 4 methyl 2 thiazolesulfenyl) -morpholine.

7. 5 carbethoxy N tert butyl 4 methyl 2- thiazolesulfenamide.

8. 5 carbomethoxy N isopropyl 4 methyl 2- thiazolesulfenamide.

9. 4 methyl 2(4 morpholinylsulfenyl) 5 thiazolecarboxylic acid.

10. The method of making a sulfenamide which comprises condensing anamine containing less than nine carbon atoms selected from the groupconsisting of morpholine, piperidine, piperazine and lower alkylsubstituted derivatives thereof ethylene diamine and ANHz Where A isselected from the group consisting of alkyl, alicyclic, aralkyl hydroxyalkyl furfuryl and tetrahydrofurfuryl groups in the presence of anoxidizing agent with a mercaptan of the structure where R and R areselected from the group consisting of hydrogen and hydrocarbon radicalscontaining less than 9 carbon atoms.

11. The method of making a sulfenamide which comprises condensingmorpholine in the presence of an oxidizing agent with a mercaptan of thestructure where R and R are lower alkyl radicals.

12. The method of making a sulfenamide which comprises condensing alower alkyl primary amine in the i5 presence of an bxidizing'agent witha mercaptan of the structure where R and R are lower alkyl radicals.

13. The methodof making a suifenamide which cornprises condensing alower alkyl primary amine in the presence of an oxidizing agent with5-carbomethoxy-4- methy1-2-thiazolethiol.

14. The method of making a sulfenarnide which comprises condensingmorpholine in-the presence of an oxidizing agent with5-carbomethoxy-4-methyl-Z-thiazoiethiol.

15. The method of making a'sulfenamide which comprises condensingmorphoiine in the presence of an oxidizing agent with'5-carbethoXy-4-methyl-2-thiazolethiol.

16. The method of making a sulfenamide which bomprises condensingtert-butylamine in the presence of an oxidizing agent With5-crabethoxy-4-methyl-2-thiazolethiol.

17. The method of making a sulfenamide which cornprises condensingisopropylamine in the presence of'an oxidizing agent withS-carbethoxyl-methyl-2-thiazolethiol.

1. AS A NEW CHEMICAL COMPOUNDS THIAZOLESULFENAMIDES OF THE STRUCTURALFORMULA
 10. THE METHOD OF MAKINGA SULFENAMIDE WHICH COMPRISES CONDENSINGAN AMINE CONTAINING LESS THAN NINE CARBON ATOMS SELECTED FROM THE GROUPCONSISTING OF MORPHOLINE, PIPERIDINE, PIPERAZINE AND LOWER ALKYLSUBSTITUTED DERIVATIVES THEREOF ETHYLENE DIAMINE AND ANH2 WHERE A ISSELECTED FROM THE GROUP CONSISTING OF ALKYL, ALICYCLIC, ARALKYL HYDROXYALKYL FURFURYL AND TETRAHYDROFURFURYL GROUPS IN THE PRESENCE OF ANOXIDIZING AGENT WITH A MERCAPTAN OF THE STRUCTURE